Michael Heizer : [publ. ... for the exhibition "Michael Heizer", June 15 - July 29, 1979 at Essen, West Germany and August 18 - October 7, 1979 at Otterlo, Nederland] / Museum Folkwang Essen ; Rijksmuseum Kröller-Müller Otterlo. [Ed. by: Zdenek Felix]. Essen, 1979